Manhole cover



' April 7, 1931. R H, T 1,799,489

MANHOLE COVER Filed May 27, 1929 Patented Apr. 7, 1931 1 UNITED s'rzxrli RALPH 11. WEST,

PANY, OF CLEVELAND, OHIO,

aconronnrron-ononto mmnonnico'vnirf,i "j

Application filed'May 27, l ag es N6. eealeaj This invention relates to manhole covers, and more particularly to the type of manhole cover which is retained in place by gravsuch as is commonly used in openings conduit tunnels, and the.

i y, leading to sewers, like. I v

, Anobject of thisinventionis to provide an improved form of manhole cover; i

. Other objects and advantages of this invention will be apparent fromthe following description taken in; connection with the a ccompanying drawings in which: I

Fig. 1 is a top plan view of one form of constructed according to my invention V Fig. 2 is a bottom plan View thereof; Fig. 3 is a sectional view taken on line 3-3 of Fig. 1;

Fig. 4 is a top plan view of another formof thecover of my invention; I

Fig. 5 is abottom plan view thereof; and Fig. 6 is asectional view taken on 'line 66 of Fig. 5.

' My invention, as shown in thedrawings,

' cmbraces two types of manholecovers though Ido not limit my invention to theseparticular types. The form shown in Figs. 1, 2 .and 3 is commonly termed the open type cover since it is constructed with openings therein which permit the passage of l ght, air and water. The form shown in Figs. 4, 5 and 6 i is constructed 'without openings and vis known as the solid type of cover.

For obvious reasons, manhole covers are usually made of cast metahandin mak ng I prefer to use cast steel because my covers, any suitof its high tensile strength, though able material may be used.

As shown in the drawings, is substantially the same-for both the open and closed types of cover.

rim 10 forms the perimeter of the cover and encloses a space which is divided into sections by heavy main ribs 11 and 12. The. ribs 11 form one group of spaced apart parallel ribs, and the ribs 12 form another such group. Each'of these groups of main ribs divides the space enclosed by rim 1O into and the two groups of ribs intersect sections, at right angles so that the ribs of one group the rib pattern so that breakageis.notlikelyto occur- Fur-t In each case a divide each of the sections formed or CLEVELAND, 01110, nssrenon. To mnwasrmm. ons rrne comv I the other group, into a I series of blocks. 1 The spaceenclosed by each block so formed 'tional area thangthe mainlribs. "These secondary ribs extend between two adja.

cent parallel main ribs',"-or between one of themain ribs andthe' rim 10.; Asthe' drawings clearly show, "infi each series of groups of secondary. ribs, groups of secondary irwhi chl are parallel with I the main ribs 11 'altern ate; with groups{of-secondary ribs which 'are parallel with main ribs 12.

' In the open type of cover, shown in-Figsn 1-,.2 and 3,.tlie t'op surfacewofthe cover is to collect-at'the center,leaving thefmargin'al I openingsg'clear for the passage oil water.

In the closed type of cover shown in Figs. 4, 5 and 6," webs14v a'recast integral with the ribs and close thefspace, between'adj acent ribs. rThese? webs, are "so placed that their upper 7 surface is depressed slightly below: the

top" surface of the ribs-'andfOt-the rim 10; i

'is spanned by a group of short secondary r ribs 13 which are of "smaller cross-secl- This construction gives-the :closedj'type of cover'substantially the same rib patternior' configuration that the open type cover has.

shown and, described vproducesa strong and To facilitate the, removal of the covers from I P manhole rings,-adepression .15 maybe proi vided in the peripheral surface of rim 10 for v rugged coverflfrom a minimum weight; of f metal. The intersecting mainribs reenforce each other and distribute loads on thecover thermore, theintersecting main ribs andtlife' alternate groups of secondary ribs'pres'entfa broken surface upon which vehicle wheels i,

will have good traction, thereby lessening the danger of skidding on-pavements 'or floorsin which these covers are used.

In providing; the'aintersecting heavy main smaller cross scctional area. In the open ribs 11' and 12, the secondaryribs 13 will be i very short and'consequently can be of much I claim type of cover, this construction has particular merit because the large area represented are circular in form, it is obvious that the coversof my invention may be made of any desired shape or contour such as square or Y oblong, andlikewise 1t is not essential .to my invention that the-secondary ribs 13 be of less cross-sectional area than the main ribs. Therefore, I do not limit' myselif toithe precise details disclosed but regard my invention as including such modifications as come with inrthespirit of the invention and; the scope oftheappended claims.

YH'aving thus described my invention, [1

1. A manhole cover, comprising a rim, intersecting main ribs attached .to said rim and dividing the area of said cover into serieszof blocks, and a group'of secondary ribs extending across each of said blocks, the ribs of alternate blocks. of each series being at I 1 right angles to the ribsof intermediate blocks of that series. 7 2.-A manhole'covercomprising a r1ni,a

set of parallel main ribs dividing'the space enclosed by said rim:into sections, asecond set of parallel main'ribs intersecting the first mentioned set of main ribs and dividing said sections into blocks, and a pluralityof secondary ribs extending across each of said blocks and supported at their'ends by adj a-, cent main ribs, the secondary ribs of one series of blocks being supported by the first mentioned set ofmain ribs and the secondary ribs of another series of blocks being supa pfrted by thefsecond mentioned set of main r1 s. I

3. A manhole cover comprising a .riin, a set of main ribs dividing the space enclosed by said rim into sections, a second set of par- 'allel main'ribs intersecting the first mentioned set of main ribs and dividing said sections into substantially square blocks, and a plurality of short secondary ribs extending across each of said blocks and supported at their ends by adjacent main ribs, the secondary ribs of alternate blocks ofeach of said sections being at right angles to the first'mentioned main ribs and the secondary ribs oi" the intermediate blocks of that section being at right angles to the second mentioned set of main ribs.

In testimony Whereofl'I hereunto ailix my signature.

i RALPHAH. WEsr 

